You probably have that stitch built-in in one or more of the machines you already have. Check the manuals, and as maniac quilter said, it is a straight stitch for about four stitches, then a zigzag, then straight stitches. The sewing machine manual will even show how to fold your fabric for the stitching. The key is to set it so the bite (zigzag) does not go too far into the folded edge of fabric.